Trimming mechanism for grinder wheels



Nmr. 9, 1948.

R. w. D lCKl ESON 2,453,501

TRIMMING MECHANISM FOR GRINDER WHEELS Filed April 5, i944 5 Sheets-Sheet 1 MI I ll v INVENTOR.

ROBERT WFDICKIESON BY ATTQ NHS,

Nov; 9, 1948. R. w. DICKIESON TRIMMING MECHANISM FOR GRINDER WHEELS 5 Sheets-Sheet 2 7 Filed Apfil 3, 1944 INVENTOR. ROBERT W. DICK! ESON ATTORNEYS Nov. 9, 1948. R. w. DICKIESON I TRIMMING MECBAIQSM FOR GRINDERWHEELS' 5 Sheets-Sheet 3 File d Aprils, 1944 mmvrox ROBERT, w. DIC'KIESQN ATTORNEYS Nov. 9, 1948. R. "w. DICKIESONV 2,453,501 TRIMMING MECHANISM FOR IGBINDER vnma'ns Filed April 3, 1944 s Sheets-Sheet 14 INVENTOR. 9 I

v ATTORNEYS Nam 9, 1194 Filed April 3, 1944 R. W. DICKIESQN ZABfiE TRIMMING MECHANISM FOR GRINDER WHEELS 5 Sheets-Sheet 5 mechanism Patented Nov. 9, 1948 UNITED STAT PA I a r-53,501 TRMMING MECHAhTISM FOR GRINDER WHEELS Robert WYDicki e s'on, Detroifii- Michi, "assig fiorl'to r The Gear Grinding Machine: Company; Ham; tramck, I Miciig a *corporatidn ofrMiohigan" A piieationfspiir1s44, SffaLNdf 529,-3'14 1 r 4*Glaims. (01. 125 11) a i 2*: v The invention relates to mechanisms' ofthat a tri in'h iin'g jrnechanitsni'may beemploy'ed inchid type designed for use in fashioning grinder wheels ing apriQtmed templetanqfapanthgraphinec for form grinding. truism?"This,howeyerfgreat1yincreasesthe c It is the object of the invention tc'obtairraf plexity and cost oftiieabparathsgkwithtnefltr simple construction ofmechanism ior'mountingt ming mechanismflforming the suhjectlmatter of on the Work carrying tableof the "grindingnia the instant intentior iiardahle td'tririirelativechine which is particularly adapted for the trim- 1y long arcuate curves without extending; the sup ming of long radius arcuate curves. portingr frame to commensurate dimensions It is a further object'of the inventiomtd pro- The geometrical principle involved in the c vide means for accurately determining the length struction is diagrammatically;illustrated-in.:Fig;.l of themes and for forming the same inltanent 1 as followss relation to other curves. y

Still further it is an object to obtain acon struction which can be compactly arranged on its;

Geometry} Ir'i a pla -n'e I; 253, Ursa coincident piahe l l r 6, 4-havi'ng a smallradius circlel drawntherein mountmg wh h 5 h a r m 1 If the" ai'tter' pian'e'fis swung'eboht an axi's 8- ii S19nsthan h of tr Fh fi i fi intoa-po'sitio'n whicfiis oblique in it'sreiatior'i to trimmed thereby. W1th ;these ob ects m new the ls an m 2 t .1 p z w L g hem invention Consists: in the nse t innate W i jection thereof'into the original' plane become 0d of operation of the trimmingmechanismias curve pposite'sid'es'of the center of theiriaio axisvery closelyapproximates true'arc; Thii i if a small arc 9 9*is drawhf from ahen'terilFwit k; 1 m w V a. 1 the" radius nfuch'grater than that' 'of-"the 'cir 2 1s a t l tl dma 1- ?4'- 1 it will bfound to almost'exactly coi'ricid withv in elevationthrough aportion of t n a pGrtibn -of 'the-"ellipse? in fact, the ifierencez t a t i .7 1 l a betweer'itliis arcarid the elliptical cu "of the a 3 1s a cross e t ste a l elin order oe'cz oran mm" such-"amfiiutefrm" also QWm rtwn in els e e y is well witniri the tolerance'liiriitsdormamfigrin 4 1 Plan 0f ithemechamsm W ing 'opratio'r'is. Making' -use' 'of this rinciple-"I5 m 3 u i l l have""constr'ucted a trimming mechanis'm in I F g. 5 is a sect on on l ne 5 gi which the trimming" point is mdvea 'througnsan e- 6 a c q 5 .F arcuate'curve bf relatiifely' small"radiusint a plarie 7 1S Plan W 4 lllustmtmg" -which is oblique td axiaipiari of th-griridfi am e for 3 adwsenemr wiieeiz'I fiis wiu triman the "crosssectionalcon Fig. 8 1s a longltudmal section of. another: p01? touriofrsafidl Wfieb} a curve which h foxfi a u 1 of h trlmmmamechamsmi anar c ofmuchiongefradms.- ccnsequentiwth 9 1S a Cross Section on lme Showf supprtirig frame of "the "trimming mechanisrir mg P F m elevatlPn; I n may b or dimensions"smalIen'thantheradiiisof -P Is n elevailon of a Portion 'a curve trimined thereby whilei-at the same time structlon shown In V V 1 sai dtrimmin'fg point will travel ah'out a fixeuaxisz'r Fig. 10 is a diagrammatic elevationillustrating in said' fram l a specific construction of work which may bevground by the trimmed grinder wheel; "and? Fig. 11 is a diagram illustrating a geometrical: principle involved in the construction ofithe trim-- Fig. 1 is a side elevation of'the tr inrin' ingineoh} anism associated with the work holder. iotfthe ming mechanism of WorK ldatI haVe illustrated iri Fi 'g. moire-sad In the present state of theartivarious trimming-l lture'fd iwl'ijfi it isjadaptii dr" This islga qz k rr mechanisms have beenlconstructedfor theitrime m 'ra' a v v u g b l an'df'a kplflfafity wof" mingof arcuate and straight line: curves :in tan? "to th-1ike portions 0, c, gent relation to each other. Usually the arcuate'i eriisi' erarsurfacez These proJe t1 curves are of relatively short'rad'ius .soithatthe" gea'r teethof ini' oliite "o1" cycloidalccdiitourw'b centers thereof 'can be located within'lf'a 'frame on tlie cdr itraryjare formed with meta-teen an of small dimensions. For trimming" arcuate topeos'ite'siaem,d' eofinecte dby small fillet' 1 curves. of large radius or for noni-archatefciirvesfi to-ifiheperipheral curvef-cdnl::eritric with the' airis b. The surfaces to be ground are d, d, e, e and f tangent to each other and the radius of each of the arcuate curves d, d is greater than the radius of the curve 1. Another characteristic of the structure is that the projections are in pairs, the members of each pair being at a predetermined angle or circular pitch in relation to each other.

while the angle between successive pairs is greater. It is unnecessary to explain the utility of this structure for that forms no part of the instant h invention.

Grinding machine S ide trimming mechanism The'grinder wheel is trimmed to a cross sectional contour corresponding to the interdental member extending axially of the frame H with its opposite ends in engagement with cylinders L and L in said frame. Between these cylinders the frame H is hollow and within this space is a cross member L centrally secured to the piston L. The opposite end portions of the member L are inclined into substantial parallelism to the surfaces H and H and are slotted for engagement with the spherical projection K at the free end of a rock arm K secured to the shank K. The slotting is at approximately the same angle at which shank K is finally located in member J on said inclined faces H and H The arrangement is such that an axial movement of the piston L will, through the members L and K5, impart a rocking movement to theshank K and a corresponding angular movement to the arm K However, the amount 'of angular movement of the arm K is determined by the length of axial movement of the piston L contour of the work and as above stated the side portions are long radius arcuate curves. H is a frame mounted on the table which is formed with oppositely inclined faces H, H on opposite sides of the axial plane of the work. Between the portio'ns H, H is a horizontal face H? for locating and supporting a gauge rest I secured by bolts I. Thi gauge member has at opposite ends thereof V-shapedcradles I for receiving like cylindrical portions 1 of a gauge I The latter is used in setting the trimming points to cylindrical surface I aswill beLhGIElllaftEl' explained. Mounted on the inclined faces H, H are members J each of which is adjusted to a predetermined angle about an axis J normal to the surface on which the member is mounted. The member J carries a tapered bearing J 2 for receiving a correspondingly tapered shank K of a diamond carrying member- K. A raw-hide seal J between J and K excludes. all-grit .or other foreign matter from the working parts; At the opposite end of the shank K is a threaded portion J having nuts J and a washer J thereon for drawing the tapered shank in close engagement with the bearing J and washer. At the inner end of the memberK A hollow cap. J securedto the member J encloses these nuts;

K 1. and holder K therefor which latter maybe adjusted by a screw K and locked by a screw K which is limited by stops at opposite ends thereof in the cylinders L and L The piston L is guided in its axial movement by a pin L extending up-. ward from the central portion thereofand carry- I inga member L which engages opposite parallel sides of a slot H in the surface H This will permit axial movement of the piston but will prevent any angular movement thereof.

Mechanism for trimming the root curve v To ,complete the fashioning of the grinder wheel, the peripheral surface thereof must be trimmed to an arcuate curve of a predetermined radius from the axis 1). This curve 1 must terminate at opposite ends in tangent fillet curves e, e which latter 'are'alsotangent to the curves d and d trimmed bythe mechanism G. The trimming mechanism G which accomplishes this result isof the following construction. M is a bifurcated frame mounted on the" table A in rear of the frame H. N is a shaft extending axially in alignment with the centers D and D having its opposite ends journaled in the furcations of't'he frame M preferably by taper roller bearings M and M Caps M and M enclose the opposite-ends of the shaft and the bearings in said furcations. Upon the portion of the shaft N extending intermediate the furcations is mounted'a housing N which is keyed to the shaft and forms an upwardly extending arm. "Journaledin the upper portion of this housing arm is a shaft 0 which is mounted preferably in roller; bearings O, O? and has its axis parallel to the axis of the shaft N. The furcation M of the frame M-is hollow and is adjacent to the housing N with a sealing ring M therebetween to exclude the entrance of dust or dirt. On the portion of the shaft N within the hollow furca- Thedistance between the diamond point and the axis of the member K is relatively short in com-;

parison with the radius of the curve which is to be trimmed by said point in the cross sectional contour of the grinder wheel. However, because of the angular adjustment of the members J on the inclined surfaces H and H about the axes J, the path of said point is in a plane at an oblique angle to the plane of rotation of the grinder wheel. This will form in the contour trimmed an elliptical curve approximately corresponding to an arcuate curve of the desired radius.

It isnecessary that the trimmed curve should be not only of the proper radius but also of a definite arcuate length. This, together with means for oscillating the arm K is preferably accomplished by the following construction. L is a piston tion M i's-secured a member P which has 01)- positely extending arms P. P are adjustable screws engaging the arms P and extending over stops P being locked. by nuts P, so that by adjusting the screws the amount of rocking move ment permitted to the shaft N is accurately determined. There is also revolubly mounted on theshaft N'adja'cent to the member Pa downwardly extending rock arm Q. The hub-Qof' this rock arm extends into the housing N and is secured to anupwardly extending arm R having a gear segment at its upper end which intermeshes-with apinion R secured to the shaft 0. The downwardly extending arm Q has at'its lower endza cylindrical portion Q which engages a1 piston 18 in a transversely extending cylinder S mounted in the lower portion of the frame M. The cylinder S iscut away atS in, its.central..

aceacdi gaging the caps S and forming stops for-con tacting lugs S on :the ends of the piston. The housing N '(Figs. 8 and 9) has a partition N therein whichis adjacent to the arm R. In this partition is a transversely extendingchannel N for receiving slidable blocks N and :a spring N between these blocks. Theiarm R has .a pair of spaced pins R projecting therefrom into the channel W and blocks N which latter have shoulders N pressed against the pins by the spring N The blocks are also sufiiciently cut awayat N opposite the shoulders N to permit independent movement of thelpins under certain conditions. i N are adjusting screws engaging'the housing N and extending into the channel N at opposite ends thereof, said screws limiting the outward sliding movements of the blocks N in the channel. They are used to set the blocks N? so there will be no play between said screws and blocks and/or no play between the blocks and pins R as end play would result in an undesirable mc-vement of diamond T With the construction as thus far described,

it will be understood that movement of the piston S in'the cylinder S will rock armR connected thereto. Movement of the arm R will be communicated to the housing N through the medium of the pins R blocks N and spring N This spring is sufliciently preloaded to normally hold the shoulders N of the blocks in contact with the pins R so that the housing N will rock with the arm R. However, as the housing N is keyed to the shaft N and the latter is keyed to the member P having the oppositely extending arms P and screws P rocking movement of the housing is limited by contact of the screws P with the stops P Thus, by adjusting the screws P the length of arcuate movement of the housing N and shaft carried thereby is accurately determined. When the housing N is at the limit of its movement, the arm R is still free to rock inasmuch as this arm is not positively connected to either the housing or the shaft N. Thus, continued movement of the arm R will cause one of the pins R to move the block N sistance of the spring N Such independent movement of the arm R will cause the gear segment thereon to communicate rotary movement to the pinion R and through the latter to rotate the shaft 0. The shaft 0 has connected to one end thereof the trimmer arm T which carries at its outer end the diamond holder T and diamond T The latter is offset from the axis of the shaft 0 so as to trace a curve concentric with this axis. The radius of this curve may be changed by adjusting the diamond holder T in the arm T so that a proper curve may be selected to form the fillets e, e connecting the root curve with the side curves d, d.

Briefly summarizing the operation above described, the housing N and arm R will travel together and without communicating any rotary movement to the shaft 0 until the screw P en gages the stop P This trims the portion of the grinder wheel corresponding to the root curve 1. Further movement of the arm R rotates the shaft 0 and causes the diamond T to trim the curve the arm Q and the in the channel N against the re-.

6 corresponding to the ifillets ie or c. This :fillet curve is exactly tangent to the -root curve -f and by iproperly adjusting the screws R it will also be'tangent to the sideicurve dord. Thefirotation of :the shaftiO is .limitedby the adjusting screw. S which when contacting with :the lug S :prevents .further movement i of .the piston S.

v'apemting mechanism The trimming mechanisms-G and G are hydraulically operated and the operation of each is controlled by-a -valve. The-detailed constructioniof thishydraulic operating mechanism is not illustrated but, in general, the frame I-I has mounted on its front face afixture U including a pair of adjacent hydraulic valves U and il Thesewalves are adjusted by handles U and U and the hydraulic connections (not shown) are such that the handle U controls the operation of the-side trimmers' while the handle U controls the operation-oftherootandfillet'trimmer. Be-

fore operating the-side trimmers the table A is i adjusted into a,positionin-relationto the grinder wheel indicated byF, Fig. 1. *The handle J is then moved *-to a a position which 'will admit -hydraulic fluid to the cylinder at the left end of the piston L to move said piston to the right. This through the rnemberL and rock arms K will simultaneously rotate the shafts-Kswinging the arms K and diamond points K downward. When-the handleU' 'is returned to its original position, the piston =L will l be actuated in the -reverse direction swinging the arms K and 'diamond points K upward Aftercompletionof the side trimming operation, the table i-s'adjusted'to a position relative to the grinder wheel illustrated at F Fig. 1. This will bring the diamond point T into the vertical axial plane of the grinder wheel after which the handle U is operated to actuate the piston S. This, as above fully described, will trim the root curve and also the tangent fillet curves at opposite ends of said root curve.

To set the diamond points K the gauge member I has its cylindrical portions I placed inthe V-shaped cradles I after which each diamond holder K is adjusted by the screwK into contact with the cylindrical surface 1 It is then locked in this position by the screw K. This will place the diamond points K at exact radial distance from the axis of the gauge member I which will properly position them for trimming the grinder wheel.

What I claim as my invention is:

l. A trimmer mechanism for grinder wheels comprising a rock shaft, a rock arm revoluble therewith, a shaft parallel to said rock shaft mounted at the outer end of said rock arm, a trimmer point mounted on the latter shaft at a predetermined distance from the axis thereof, a second rock arm independently revolubly mounted on said rock shaft, resilient yieldable means coupling said rock arms, a connection between said second rock arm and the shaft carryingsaid trimmer point whereby said shaft will be rotated by independent rocking movement of saidsec- 0nd rock arm, a stop for limiting the angular movement of said first mentioned rock arm, a stop for limiting the movement of said second rock arm positioned to permit movement of the latter after arrest of movement of said first rock arm, whereby said trimming point will first trace a curve about the axis of said first mentioned shaft and will then trace a short radius curve tangent to the first curve about the axis'of-said second mentioned shaft.

2. A trimming mechanism for a grinder wheel, comprising a frame having a pair of supporting surfaces at opposite oblique angles to the plane of rotation of said grinder wheel and on opposite sides thereof, a rock shaft mounted on each of said surfaces with its axis parallel thereto and extending at an oblique angle to the line of intersection between said surfaces and the plane of rotation of the grinder wheel, rook arms connected to said rock shafts, trimmer points carried by said rock arms, a cradle on said frame centrally between said oblique surfaces adapted to receive a cylindrical member seated in said cradle forming a gauge for setting said diamond points, and means for rocking said rock shaft to cause said trimmer points to trace arcuate curves in the trimmed surfaces on opposite sides of said grinder wheel.

3. In a trimming mechanism, a pair of coaxial rock arms, a resiliently yieldable connection between said rock arms for normally moving the one with the other, a shaft carried at the outer end of one of said rock arms, a trimmer point mounted on said shaft, a connection between said shaft and the other rock arm for causing rotation of said shaft upon relative movement of said rock arms, actuating means for the last mentioned rock arm, and stops for limiting the rocking movement of said first mentioned rock arm whereby said trimmer point will trace a long radius curve while said rock arms move together and will trace a short radius tangent curve by the independent movement of the second rock arm.

4. In a trimming mechanism, a rock shaft, a

housing fixedly mounted on said rock shaft and extending radially therefrom, a second shaft journaled at the outer end of said housing parallel to said rock shaft, a trimmer. point carried by said second shaft a predetermined distance from the axis thereof, a rock arm rotatively mounted on said first mentioned shaft extending radially within said housing, a gear segment at the outer end of said rock arm, an intermeshing gear segment on said second shaft, yieldable connecting means between said rock arm and housing for normally causing thesarne to move together, means for rocking said rock a-rm through a predetermined angle of movement, and adj ustable stops for limiting the rocking movement ofsaid housing to less than that permitted to said rock arm whereby said trimmer point will trace a long radius arcuate curve during the rocking of said housing and short radius tangentcurves at opposite ends of said long radius curve during the independent movement of said rock arm.

ROBERT W. DICKIESON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 30 Number Name Date 2,118,902 Spicacci May 31, 1938 2,301,610 Brady Nov. 10, 1942 2,311,302 Wildhaber et a1 Feb. 16, 1943 2,363,293 Carlsen Nov. 21, 1944 5 2,398,451 Schantz Apr. 16, 1946 

